The constant challenge in the wind industry is to increase the output power of the turbines at the same time as reducing weight. A current trend is to use permanent magnet generators in order to exclude the gearbox and thus decrease the total weight. These solutions often require a speed feedback encoder mounted on the main shaft between the generator and the rotor blades where the shaft dimension is large – sometimes around a meter. For such demands, Leine & Linde has developed a new magnetic ring encoder with many features specially designed for the wind industry.
Called the Leine & Linde MRI 2000, this encoder is designed as a ring segmented into pieces, something that facilitates commissioning and service. As the ring is often mounted on a shaft between other parts in the machinery, it may be difficult to access it, both when first mounting it and when performing service. With a segmented ring, the pieces may be mounted from two sides of the shaft and screwed together. The segments also make handling easier when transporting and storing the ring.
Fixing the ring to the shaft can be made through flange mounting with axial screws or by Leine & Linde’s ClampFit solution for simplified commissioning. With ClampFit, the ring segments are screwed together in a way that automatically tightens the ring around the mating shaft. This saves commissioning time and enables fixing to a standard cylindrical shaft without any flange expansion prepared.
The speed pickup unit is available with several market standard interfaces for incremental signals. The interfaces High Current HTL and Optolink have been specially designed for long distance transmission, which makes them extra suitable for crane applications or for turbine designs where the encoder signals need to be transferred from the top of the tower down to the ground.
Heidenhain for Leine & Linde
Filed Under: Encoders, News